Loans and Loans Held for Sale - Restructured Loans for Periods Stated (Detail) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2014 SecurityLoan		Jun. 30, 2013 SecurityLoan		Jun. 30, 2014 SecurityLoan		Jun. 30, 2013 SecurityLoan
Financing Receivable, Modifications [Line Items]
Number of Loans	7		25		19		54
Pre-Modification Outstanding Recorded Investment	$ 233,000	[1]	$ 5,713,000	[1]	$ 2,042,000	[1]	$ 8,685,000	[1]
Post-Modification Outstanding Recorded Investment	229,000	[1]	5,694,000	[1]	2,019,000	[1]	8,278,000	[1]
Total Difference in Recorded Investment	4,000		(19,000)		(23,000)		(407,000)
Debt forgiveness to customers			100,000
Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1		0		1		7
Pre-Modification Outstanding Recorded Investment	129,000	[1]	0	[1]	129,000	[1]	2,260,000	[1]
Post-Modification Outstanding Recorded Investment	127,000	[1]	0	[1]	127,000	[1]	1,873,000	[1]
Total Difference in Recorded Investment	(2,000)		0		(2,000)		(387,000)
Chapter 7 Bankruptcy [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	6	[2]	23	[2]	17	[2]	45	[2]
Pre-Modification Outstanding Recorded Investment	104,000	[1],[2]	623,000	[1],[2]	894,000	[1],[2]	1,335,000	[1],[2]
Post-Modification Outstanding Recorded Investment	102,000	[1],[2]	604,000	[1],[2]	873,000	[1],[2]	1,315,000	[1],[2]
Total Difference in Recorded Investment	(2,000)	[2]	(19,000)	[2]	(21,000)	[2]	(20,000)	[2]
Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	[3]	1	[3]	0	[3]	1	[3]
Pre-Modification Outstanding Recorded Investment	0	[1],[3]	4,339,000	[1],[3]	0	[1],[3]	4,339,000	[1],[3]
Post-Modification Outstanding Recorded Investment	0	[1],[3]	4,339,000	[1],[3]	0	[1],[3]	4,339,000	[1],[3]
Total Difference in Recorded Investment	0	[3]	0	[3]	0	[3]	0	[3]
Maturity Date Extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0		1		1		1
Pre-Modification Outstanding Recorded Investment	0	[1]	751,000	[1]	1,019,000	[1]	751,000	[1]
Post-Modification Outstanding Recorded Investment	0	[1]	751,000	[1]	1,019,000	[1]	751,000	[1]
Total Difference in Recorded Investment	0		0		0		0
Commercial Real Estate [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1		0		1		3
Pre-Modification Outstanding Recorded Investment	129,000	[1]	0	[1]	129,000	[1]	1,541,000	[1]
Post-Modification Outstanding Recorded Investment	127,000	[1]	0	[1]	127,000	[1]	1,288,000	[1]
Total Difference in Recorded Investment	(2,000)		0		(2,000)		(253,000)
Commercial Real Estate [Member] | Chapter 7 Bankruptcy [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	[2]	4	[2]	0	[2]	7	[2]
Pre-Modification Outstanding Recorded Investment	0	[1],[2]	53,000	[1],[2]	0	[1],[2]	258,000	[1],[2]
Post-Modification Outstanding Recorded Investment	0	[1],[2]	51,000	[1],[2]	0	[1],[2]	255,000	[1],[2]
Total Difference in Recorded Investment	0	[2]	(2,000)	[2]	0	[2]	(3,000)	[2]
Commercial Real Estate [Member] | Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	[3]	1	[3]	0	[2]	1	[2]
Pre-Modification Outstanding Recorded Investment	0	[1],[3]	4,339,000	[1],[3]	0	[1],[3]	4,339,000	[1],[3]
Post-Modification Outstanding Recorded Investment	0	[1],[3]	4,339,000	[1],[3]	0	[1],[3]	4,339,000	[1],[3]
Total Difference in Recorded Investment	0	[3]	0	[3]	0	[2]	0	[2]
Commercial and Industrial [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans					0		1
Pre-Modification Outstanding Recorded Investment					0	[1]	392,000	[1]
Post-Modification Outstanding Recorded Investment					0	[1]	387,000	[1]
Total Difference in Recorded Investment					0		(5,000)
Commercial and Industrial [Member] | Chapter 7 Bankruptcy [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans					1	[2]	1	[2]
Pre-Modification Outstanding Recorded Investment					287,000	[1],[2]	3,000	[1],[2]
Post-Modification Outstanding Recorded Investment					286,000	[1],[2]	3,000	[1],[2]
Total Difference in Recorded Investment					(1,000)	[2]	0	[2]
Commercial and Industrial [Member] | Maturity Date Extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0		1		0		1
Pre-Modification Outstanding Recorded Investment	0	[1]	751,000	[1]	0	[1]	751,000	[1]
Post-Modification Outstanding Recorded Investment	0	[1]	751,000	[1]	0	[1]	751,000	[1]
Total Difference in Recorded Investment	0		0		0		0
Commercial Construction [Member] | Maturity Date Extension [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans					1		0
Pre-Modification Outstanding Recorded Investment					1,019,000	[1]	0	[1]
Post-Modification Outstanding Recorded Investment					1,019,000	[1]	0	[1]
Total Difference in Recorded Investment					0		0
Residential Mortgage [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans					0		2
Pre-Modification Outstanding Recorded Investment					0	[1]	153,000	[1]
Post-Modification Outstanding Recorded Investment					0	[1]	153,000	[1]
Total Difference in Recorded Investment					0		0
Residential Mortgage [Member] | Chapter 7 Bankruptcy [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1	[2]	2	[2]	5	[2]	8	[2]
Pre-Modification Outstanding Recorded Investment	52,000	[1],[2]	84,000	[1],[2]	329,000	[1],[2]	353,000	[1],[2]
Post-Modification Outstanding Recorded Investment	52,000	[1],[2]	75,000	[1],[2]	327,000	[1],[2]	344,000	[1],[2]
Total Difference in Recorded Investment	0	[2]	(9,000)	[2]	(2,000)	[2]	(9,000)	[2]
Home Equity [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans					0		1
Pre-Modification Outstanding Recorded Investment					0	[1]	174,000	[1]
Post-Modification Outstanding Recorded Investment					0	[1]	45,000	[1]
Total Difference in Recorded Investment					0		(129,000)
Home Equity [Member] | Chapter 7 Bankruptcy [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	4	[2]	17	[2]	10	[2]	23	[2]
Pre-Modification Outstanding Recorded Investment	43,000	[1],[2]	486,000	[1],[2]	269,000	[1],[2]	648,000	[1],[2]
Post-Modification Outstanding Recorded Investment	41,000	[1],[2]	478,000	[1],[2]	251,000	[1],[2]	640,000	[1],[2]
Total Difference in Recorded Investment	(2,000)	[2]	(8,000)	[2]	(18,000)	[2]	(8,000)	[2]
Installment and Other Consumer [Member] | Chapter 7 Bankruptcy [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1	[2]	0	[2]	1	[2]	6	[2]
Pre-Modification Outstanding Recorded Investment	9,000	[1],[2]	0	[1],[2]	9,000	[1],[2]	73,000	[1],[2]
Post-Modification Outstanding Recorded Investment	9,000	[1],[2]	0	[1],[2]	9,000	[1],[2]	73,000	[1],[2]
Total Difference in Recorded Investment	$ 0	[2]	$ 0	[2]	$ 0	[2]	$ 0	[2]

[1] Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

[2] Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.

[3] This loan had debt forgiveness of $0.1 million to the customer; however, the loan was previously charged off to a balance below the actual contractual balance.